Over the past 5 years there have been reports of type 2 diabetes (DM2) in minority children in the U.S., including Mexican Americans (MA). Locally, in the past 3 years more MA children were seen with DM2 than type 1 diabetes (DM1), although the incidence of DM1 has not decreased. While the high prevalence and rising incidence of DM2, related risk factors and co-morbidities in MA adults is extensively documented, minimal information is available on the prevalence or incidence of these problems in MA children who share the same genetic heritage and live in the same environment. Even less is known about the natural progression from genetic risk to overt disease in children. Therefore, the specific aims of this proposal are to: 1. Determine the prevalence of risk factors, hyperinsulinism, impaired fasting glucose and diabetes in a homogenous group of approximately 2000 MA children 4th grade, 9 and 10 years of age) (Phase 1) 2. Explore the relationship between risk factors and glucose homeostasis abnormalities in approximately 300 MA children using a detailed clinical assessment and extensive biochemical investigations. The children will be in 3 subsets: impaired fasting glucose, high-risk, and low risk. (Phase 2). 3. Examine the temporal change in physical and biochemical parameters in the 3 subsets over 4-years (Phase 3). Children will be seen annually, because this is a period of dynamic physical change. Completion of the proposed studies will provide an estimate of the prevalence of glucose homeostasis abnormalities in MA children, increase understanding of the metabolic abnormalities at a relatively early age and stage, permit an examination of the natural progression of these abnormalities, and provide an assessment of the applicability of the new American Diabetes Association guidelines for screening MA children.